neodymium ring magnet for loudspeaker

Rings neodymium magnets (Nd-Fe-B) are composed of neodymium, iron, boron and a few transition metals in rings sharps.
These magnets are extremely strong for their small size, metallic in appearance and found in simple shapes such as rings, blocks and discs. Their max energy product can be 35MGOe~50MGOe, Neodymium magnets are developed rapidly and applied widely due to their perfect characteristic, rich raw material resource and reasonable price.

Neodymium magnets have a somewhat lower maximum operating temperature than other types of magnetic materials, so this should be considered when choosing a grade. Neodymium magnets (sintered NdFeB) are more powerful than any other permanent magnet material on the market today. Various grades of neodymium magnets are available with varying temperature and MGO characteristics. All neodymium magnets oxidize fairly rapidly when exposed, so an anti-corrosive coating (usually electroplating) is used to extend their useful lifespan. Extreme care must be excercised when handling neodymium magnets as they can easily pinch fingers. NdFeB magnets are not suitable for children because of it's strong magnetic strength.